Figure 3.
BioFET average transfer curves (MOSFET Ids as a function of the Vref applied by the reference electrode), with standard deviations, obtained by using as extended gate (EG) a biofunctionalized gold electrode (black curve) or a bare gold one (red curve). The Vref applied during the biosensing experiments (400 mV) is highlighted by a vertical dashed line. The range of the starting Ids values (around ten μA) is highlighted by the grey area. Inset: both extraction of the threshold voltage (Vth) from a representative curve, by a linear extrapolation method [35], and the correspondence between Ids and Vth changes are shown.